Excellent food for thought Mike. Like you, I often remove the editor's ink on photos.
I believe removing ugly ink greatly adds to the photo by subtraction.
If one was to add ink to cover a blemish...now that would be a different story.
A few years ago I spoke with a retired library archivist regarding removing touch ups, shading and other editor's ink. He said that many photos used in old newsrooms (where I obtain most of my new stuff) probably have had ink placed, removed and then replaced over the years. He went on to say that even saliva was used to removed excess ink. Yuck
! His opinion is that if damage from removal of ink was to occur to photos that are 75+ years old, we would have seen it already. After speaking to him I began looking for photos where I can see remnants of removed ink. To my surprise, I found a lot of photos that were touched up, cleaned and retouched. I found no sign of deterioration near the removal areas. Most damage I see to photos is from clumsy human handling.
Regarding disclosure of ink removal...I'd like to hear more of your opinions.